Production of cut sunflower under water volumes and substrates with coconut fiber

This study aimed to evaluate the production of cut sunflower in response to different water volumes and substrates, composed of soil and coconut fiber. Two simultaneous experiments were conducted in greenhouse, located in the Horticulture Sector of the Federal Rural University of Rio de Janeiro (UFRRJ), Seropedica - RJ, Brazil (22 degrees 48' S, 43 degrees 41' W and altitude of 33 m), between April and June 2016. Water was applied by an Simplified Irrigation Controller (SIC), allowing the application of different volumes (33, 67 and 133% of retention capacity of substrate) in comparison to the control treatment (100%). The substrates used were 1/3 of coconut fiber and 2/3 of soil (v/v) (Experiment 1), and 2/3 of coconut fiber and 1/3 of soil (Experiment 2). The experimental design was completely randomized, with 5 replicates. The treatment with 100% of the volume applied by the SIC led to best growth of sunflower, increasing the potential income obtained with stems at better marketing standard according to the prices practiced.